The present invention concerns an arrangement for alteration of information as generated by time-pieces having displays of the electronic type. From purely mechanical time-pieces provided with spring balance wheels and mechanical motors, changes over the years have lead to increasing reliance on electrical and electronic means for constituting a time-base. Up until very recently however, such newer generation of time-pieces continued to be provided with the usual mechanical display in which the time of day was read by observing the position of the hands. Generally, digital type presentation of information has been confined to a calendar disk which enables the date to be read through a window of the dial. More recently, there has been a trend on the part of designers to abandon the mechanical type of display in which electrical signals are transmitted into mechanical movements, in favor of purely electronic displays. Time-pieces may thereby be constructed in which there are no moving parts. Displays may continue to be of the analog type in which a pattern of radially arranged line segments about a time-piece dial is successively activated and deactivated. However, the present trend seems to prefer purely digital displays in which a succession of numbers appear on the face of the dial. Such numbers may be formed by line segments arranged in particular patterns, the segments being activated or deactivated through digital decoding circuits. The line segments themselves may be formed from known electrooptic elements such as, for example, light emitting diodes or liquid crystals.
Should it be desired to display four different information sequences in a permanent fashion, i.e. seconds, minutes, hours and calender, it has been found that problems may arise with respect to the power consumption as well as the overall dimensions and complexity of the time-piece. This can constitute a serious problem, particularly with wrist-watches since they must be closely limited in their overall dimensions. Furthermore, the power cells used to energize them should provide a certain minimum life, at present generally about one year.
In considering displays of the digital type, a further problem arises when, for one reason or another, the user wishes to change the information displayed. Time-pieces of the type under consideration generally employ a quartz crystal as the time base and can be regarded as highly accurate, i.e. approximately 5 seconds variation per month. Nevertheless even this small amount of variation may be intolerable to the user of such a time-piece. Furthermore, it will always be necessary to reset such a time-piece to the exact hour, minute and second whenever the power cell is changed. It is also generally necessary to correct the calendar display from time to time. Should the user be a frequent traveller then it is desirable that he be able to change the hour indication whenever a time zone is crossed.
To provide these several types of corrections or information alterations it is of course possible to provide as many control means as there are functions to be realized. One can, for example, provide a control resembling the traditional winding stem on a mechanical watch, which control would operate through electro-mechanical arrangements, and could be moved to various positions to effect its control functions. Alternately a separate pushbutton may be provided for each type of information to be displayed or corrected. Arrangements such as these have the advantage of being readily understood by the user, but lead to greater complexity in the construction of the time-piece and are of somewhat doubtful reliability. Where a large number of push-buttons are used they will in general detract from the appearance of a time-piece.